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NF&R Review

From: Rinke Hoekstra <hoekstra@uva.nl>
Date: Wed, 6 May 2009 12:22:33 +0200
Message-Id: <C0B8F7B3-F1B0-4953-B122-39B7670E3A03@uva.nl>
To: OWL 2 <public-owl-wg@w3.org>
Hi all,

This review completes my ACTION-333 (Christine, apologies for the  
delay, I hadn't taken the annual Dutch April/May-holiday season into  

Overall I think the document is in good shape! (the examples look  
great) On top of Peter's comments, there still are several things I  
would like to remark. Most changes require minimal effort for maximal  
impact (I hope). I could help out if necessary.

I will try to do a more detailed review of section 2 in the coming  
week (to flesh out possible typos etc.)


The summary of my main comments is the following:

* The current situation where use cases are listed in an appendix, but  
are prominently present throughout section 2, and in section 5 is not  
good. Given that we moved use cases to the appendix, references to the  
use cases should be removed from sections 2-4, and *either* replaced  
by references to the literature *or* removed altogether (only refer  
from the use cases to the features and not the other way around). The  
table in Section 5 can replace the one in 7.1 and could be altered to  
form the 'switchboard' between features, use cases and references to  
literature (see below): these are the *real* use cases. Essentially  
this means a  move from a feature->use case->literature scheme to a  
feature->literature->use case scheme. I understand this may be a bit  
harsh/controversial, but the current solution is half-baked.

* There are some features of OWL 2 (or changes wrt. OWL 1) that are  
not listed in the current version. I identified the following:
  - imports & versioning (import by location etc.)
  - URI -> IRI
  - rdf:text
  - Manchester Syntax (is mentioned, but only as example in sections  
4.1 and 4.2)
  - Built-in datatypes (section 4 of Syntax)
  - ... more?

* I agree with Peter that the document contains too many subsections.  
Promoting the subsections of section 2 to full sections would improve  
readability and structure, and make the document more similar to other  
documents published by the WG.

* The numbering of sections has changed since the LC publication of  
April, references from e.g. the Document Overview should be updated.

These more detailed comments concern the May 5 version of the document  

Section 1
* The introduction should describe the contents of the document in the  
order they appear. If the second paragraph (i.e. the last two  
sentences) of this section is moved to after the first sentence of the  
first paragraph, the section becomes more readable.
* I think Section 4.2 is a candidate for inclusion in the Introduction  
(as Section 1.1), it demystifies a number of issues that were of  
primary concern to some of the last-call commenters. As it is included  
at this moment, it doesn't really fit after Section 4.1 anyway. If 4.2  
is moved to 1.1, then 4.1 could become section 4 (with the title  

Section 2
* Perhaps it would be good if the document specifies what it means by  
"Feature", apparently these are all language features, i.e. things you  
may express using the language for the purpose of building an  
ontology. There are other types of features (or perhaps 'aspects' of  
the language), such as the profiles, versioning and the syntaxes that  
are of a different type. Making this distinction explicit is  
important. This could be done by renaming Section 2 to something like  
"Language Constructs", or "Entities, Expressions and Axioms" (cf. the  
Syntax document). Of course, this is not necessary if its subsections  
are promoted to independent sections.

* I have said this before, and still stand by it: I do not see any  
reason for numbering the features in this section, and think the  
numbers should be removed. No other document does this, and the only  
place the numbers are reused is in the "Recapitulative Table"... and  
even here, just using their descriptive names is much more  
informative. Secondly, not all 'features' in section 2 have a feature  
number (e.g. axioms on annotation properties, top & bottom).

In a limited form, the same holds for the use cases: to me, having Use  
Case #1 described in section 7.2, and Use Case #2 in section 7.3 is  
unintuitive. Also, the hash symbols are superfluous.

* Minor qualm (again something I've said before). What is the reason  
for the prominence of the use-case domains in the examples? To me they  
don't add much, other than in the additional examples of OWL 2 use. If  
it is to make the case for a feature stronger, then all features  
should at least be supported by two use-case domains (or use case- 
domains). Still, some have only a HCLS use case, which, in my view,  
really weakens the 'case' for the feature. There are two ways out of  
this, one: add examples (not cases) from other domains for each  
feature, or two: remove the mention of the use case domain. In a way,  
the former is related to Peter's comments on lack of rationale for  
some features.

* On the references to use cases: why not use the descriptive name of  
the use cases? This would improve readability. And, given Bijan's view  
on the Appendix with use cases, perhaps these references should not  
point to the appendix, but rather directly to the literature. (see  

* I don't see the distinction between sections 2.6 (other innovations)  
and 2.7 (minor features). This can be one section.

* Section 2.5.1, indents do not work (I had a hard time finding  
ontology annotations). I propose to split this subsubsection into two.

Section 3
* I propose to promote the introduction of Section 3.1 to be the  
introduction of Section 3 as a whole. Section 3.2 could then become  
Section 3.1, and Section 3.1.1, 3.1.2, and 3.1.3 may be promoted to  
Sections 3.2, 3.3 and 3.4 respectively. The reason is that both the  
intro to 3.1 and 3.2 are introductory material that may be of interest  
to many people, while sections 3.1.1-3.1.3 are not.
* (Sidenote: in fact, I am not entirely sure that sections 3.1.1-3.1.3  
are appropriate to NF&R)

Section 4
* See also section 1
* In 4.1, the indents do not work. I propose to switch to subsections.
* 'dropping the frame-like syntax' is an almost exact copy of section  
12.1 in the October 2008 WD of the Syntax document. The original  
version is more readable.

* "XML Schema [XML Schema] called XML_Serialization OWL/XML. " should  
be "XML Schema [XML Schema] called XML Serialization."
* Reference to [UML] is not a link.

Section 5
* I looked up "Recapitulative": it is not a word. Perhaps rename to  
"Overview of Features and Use Cases"
* I don't think the examples are necessary here, it only causes excess  
* This table is more informative than the one in Section 7.1, and I  
suggest this table is moved to that section to replace the one that is  
currently there.
* I propose a three column table: Use Case, Features, Literature
* The 'Legend' table can be dropped, as all features are referred to  
using their descriptive name.
* The table should use the new table style from the css

Section 7
* See my earlier remark on numbering. If features refer directly to  
literature, numbering of use cases can be dropped.
* Some use cases mention their domain, others don't (e.g. 7.11). If  
you ask me, all mentions of domains can be removed: excess clutter. I  
think it is a leftover from an earlier version of this document that  
identified types of users etc.
* Whether a use case is used in the example of a feature is not very  
interesting, in my book. I'd rather have links to all its features,  
rather than just to the example. I suggest the example-links are  

[1] http://www.w3.org/2007/OWL/wiki/index.php?title=New_Features_and_Rationale&oldid=23143
Drs Rinke Hoekstra

Leibniz Center for Law      |  AI Department
Faculty of Law              |  Faculty of Sciences
Universiteit van Amsterdam  |  Vrije Universiteit
Kloveniersburgwal 48        |  De Boelelaan 1081a
1012 CX  Amsterdam          |  1081 HV Amsterdam
+31-(0)20-5253499           |  +31-(0)20-5987752
hoekstra@uva.nl             |  hoekstra@few.vu.nl

Homepage: http://www.leibnizcenter.org/users/rinke
Received on Wednesday, 6 May 2009 10:23:20 GMT

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